{"id":"CVE-2026-61597","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-61597","summary":"djust is vulnerable to stored/reflected XSS via javascript: URLs in built-in component template tags","details":"### Impact\nMany djust built-in component template tags (`djust.components.templatetags.*`) render a developer/user-supplied URL into an `href` / `action` attribute, HTML-escaping it with `conditional_escape` but **never validating the URL scheme**. HTML escaping prevents attribute breakout but does not neutralize a `javascript:` URI (which needs no escapable characters), so a URL value of `javascript:alert(document.cookie)` lands verbatim in `<a href=\"javascript:alert(document.cookie)\">` and executes in the victim's session on click.\n\nAffected sinks (executing href/action contexts; not exhaustive): breadcrumb (`djust_components.py:1535`; `_advanced.py:1999,2022`), `dj_nav` link/dropdown/brand (`djust_components.py:5632,5779,5807,5830`), citation URL (`:6936`), cookie-consent privacy link (`:8240`), error-page action (`_advanced.py:1728`), form `action` (`_forms.py:1239`). `<img src>` sinks are lower risk (javascript: does not execute via img src). No scheme validation exists anywhere in the component tags; a docstring at `djust_components.py:781` even acknowledges the `javascript:` risk without mitigating it.\n\n**Severity Medium:** XSS in the victim's authenticated session whenever an app renders one of these components with a URL sourced from user-controllable data; for `href` requires a click, worst case is the stored variant (URL persisted from one user, rendered to another). Conditional on developer usage, hence Medium rather than High.\n\nReproduced: `breadcrumb(items=[{\"label\":\"Home\",\"url\":\"javascript:alert(document.cookie)\"}])` emits `<a ... href=\"javascript:alert(document.cookie)\">Home</a>`; `JaVaScRiPt:` case variant also passes; `https://` URLs are preserved.\n\n### Patches\nAdd a `safe_url()` helper that neutralizes non-allowlisted schemes (`javascript:`, `vbscript:`, `data:`) to `#` while preserving http/https/mailto/tel/relative/anchor URLs, and route every href/action/formaction/xlink:href sink through it (then HTML-escape). Add a regression + an audit_ast/system-check rule flagging un-routed URL-attribute interpolation.\n\n### Workarounds\nDo not pass user-controllable URLs to the affected built-in component tags; pre-validate URL schemes in application code before binding them to component arguments.\n\n### References\nReproducer + finding writeup retained privately by the maintainer.","published":"2026-09-16T21:50:53Z","modified":"2026-09-16T22:00:04.819562472Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"PyPI","name":"djust","fixedVersion":"1.0.7"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/djust-org/djust/security/advisories/GHSA-4mf4-73j6-mvrw"},{"type":"PACKAGE","url":"https://github.com/djust-org/djust"},{"type":"WEB","url":"https://github.com/djust-org/djust/releases/tag/v1.0.7"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-16T22:00:04.819562472Z"}}